/**
 * ***************************************************************************** Copyright (c) 2003,
 * 2006 Subclipse project and others. All rights reserved. This program and the accompanying
 * materials are made available under the terms of the Eclipse Public License v1.0 which accompanies
 * this distribution, and is available at http://www.eclipse.org/legal/epl-v10.html
 *
 * <p>Contributors: Subclipse project committers - initial API and implementation
 * ****************************************************************************
 */
package org.tigris.subversion.subclipse.ui.console;

/** Simple circular buffer that stores a fix number of lines. */
public class ConsoleDocument {
  public static final int COMMAND = 0; // command text
  public static final int MESSAGE = 1; // message received
  public static final int ERROR = 2; // error received
  public static final int STATUS = 3; // status text
  public static final int DELIMITER = 4; // delimiter text between runs

  private int[] lineTypes;
  private String[] lines;

  private int writeIndex = 0;
  private int readIndex = 0;

  private static final int BUFFER_SIZE = 200;

  protected static class ConsoleLine {
    public String line;
    public int type;

    ConsoleLine(String line, int type) {
      this.line = line;
      this.type = type;
    }
  }

  /** Creates an empty console document. */
  public ConsoleDocument() {}

  /** Clears the console document. */
  public void clear() {
    lineTypes = null;
    lines = null;
    writeIndex = 0;
    readIndex = 0;
  }

  /** Appends a line of the specified type to the end of the console. */
  public void appendConsoleLine(int type, String line) {
    if (lines == null) {
      lines = new String[BUFFER_SIZE];
      lineTypes = new int[BUFFER_SIZE];
    }
    lines[writeIndex] = line;
    lineTypes[writeIndex] = type;

    if (++writeIndex >= BUFFER_SIZE) {
      writeIndex = 0;
    }
    if (writeIndex == readIndex) {
      if (++readIndex >= BUFFER_SIZE) {
        readIndex = 0;
      }
    }
  }

  public ConsoleLine[] getLines() {
    if (isEmpty()) return new ConsoleLine[0];
    ConsoleLine[] docLines = new ConsoleLine[readIndex > writeIndex ? BUFFER_SIZE : writeIndex];
    int index = readIndex;
    for (int i = 0; i < docLines.length; i++) {
      docLines[i] = new ConsoleLine(lines[index], lineTypes[index]);
      if (++index >= BUFFER_SIZE) {
        index = 0;
      }
    }
    return docLines;
  }

  public boolean isEmpty() {
    return writeIndex == readIndex;
  }
}
